song04 generates an ambient soundscape of detuned sine waves. the sine waves
are clustered together at specific frequencies, with their exact characteristics
determined by the input file s4_param.txt. the output can be written to a file,
directly to audio output, or both simultaneously (with some serious performance
degradation).

song04 can generate a maximum of 1024 sine waves. on modern PCs, it is possible
to generate approximately 200 sine waves and play them back live (tested on a
1.6GHz core 2 duo and a 3.0 GHz celeron). if your computer is slower, the
output may glitch and it may also be difficult to regain control of your PC.
keep hitting Ctrl-C until song04 is killed. if this happens, try reducing the
number of sine waves or render your output to .wav. rendering a full 1024
sine waves is time consuming, but the output can be quite pretty.

this project came out my work writing music for the ADSP-218x DSPs. this song
is a generalization of one of the first songs i made for a DSP. it's nice
and interesting and fun to modify parameters to see what the output will sound
like. it's edutainment!

song04 is designed to run at the command prompt (aka a DOS box). to launch a
command prompt, double-click on the shortcut called "song04-cmd" in the
directory where the contents of song04.zip were unzipped. double-clicking
song04.exe directly won't do anything other than output help and immediately
exit.